Mechanism for preregistering printing and other plates



Sept. 14, 1954 w, HUCK 2,683,803

MECHANISM FOR PREREGISTERINGPRINTING AND OTHER PLATES Filed NOV. 14,1949 2 She ets-Sheet 1 lNVENTOR Wuum E Hucm ATTORNEY W. F. HUCK Sept.14, 1954 MECHANISM FQR PREREGISTERING PRINTING AND OTHER PLATES FiledNOV. 14 1949 2 Sheets-Sheet 2' 36 INVENT'OR WILLIAM E Hvcn ATTORNEYPatented Sept. 14, 1954 MECHANISM' FOR PREREGISTERING PRINTING AND OTHERPLATES William HuckJForeSt Hills, N. Y., a ssignor to- Huck Co., NewYork, N. Y., a partnership Application November 14, 1949, Serial No.127,191

a 1 This invention relates to printing and more particularly to machinesand mechanisms that may be used to preregister a series of flexiblecolor-printing plates, thereby assuring that the plates will be inregister when they are placed-on the plate cylinder or cylinders ofa-printing machine; i H. It is wellknown that colored pictures fornewspapers, magazines" and other publications are printed by'a pluralityof colors, the various colors blending to produce'the finished picture.Itis obviousthat 'a' high class *colored picture cannot be obtainedunless each of the-various colors is imprinted in register with theother colors. "Furthermore, any mechanism that is used to insure thatthe plates will print in register must be easy to operate and-rapidinitsoperation. Otherwise much valuable time will be lost and the costof thefmished products-will be unreasonably high.

*Inthe past many attempts have been made to provide machines, methods;and mechanisms, that will assure-accurate and "rapid register of colorprinting plates. However, much has been left to be desired, an-dtherefore one object of the present invention is to provide an improvedmachine for registering a series of color printing plates. Anotherobject of the invention is to provide an improved plate preregisteringmechanism, whereby a series of color printing platescanbe registeredawayfromthe printing cylinder or cylinders onwhich they are eventually to beused. In the past, some of the inaccuracies that have crept into colorprinting have been dueto residual stresses and deformations that existedin the printing plate before the registering operation. Otherinaccuracies have been caused by stresses and deformations that aredeveloped during the registering operation. Therefore, itis a furtherimportant object of the present invention to provide a plate registeringmechanism that will not only relieve any residual stresses ordeformations that may have existedin the printing plate before theregistering operation, but also to provide an improved registering.mechanism that'will operate on the printing plate without causingstresses or deformations.

A still further object of the invention is to;provide an improved platepreregistering mechanism, whereby the printing plate being registered isheld in a curved form during the registering operation.

Still another object of the invention is toprovide an improved plateregistering mechanism wherein the printing plate is held stationaryduring the registering operation.

Other and important objects "or the invention will be apparentfrom'following specificationand appended claims. s

For a more complete understanding of this in- .19 Claims. (01. eel-184.5

2 vention reference should be had to the accompanying drawings-whichform part of this specification. In these drawings:

Fig. 1 is a side eleva-tional view of a machin embodying the presentinvention, portions of the machine being seen" in section as takenalongthe 'broken-line-F-I of Fig.2; r I s Fig: 2 is-a plan view of themachine shown in Fig; 1, parts of Fig. 2 being brokenaway to showelements located belowthe upper portions of the machine; a

Fig; 3 is a slightly enlarged detail view "of a register device whichforms part of the machine shown in Fig. l as seen along the line- 3-3thereof; -"Fig. 4 is afurther enlarged view, partly in section; of theregister device shown inFig. 3'and "a seen along the'line 4'4 of Fig.-3; and

Fig. 5 is an enlargedview of one of theregister adjusting devices asseenalong the line 5+5- of Referring-primarilyto-Figs. l-and Zthis'inventionis shown as having a vertical support column llythelower end ofwhichisprovided with a base r2. The upper end of the column ll supports abox-like table indicated generally by the numeral 13. The table I3 is inthe form of a hollow box and is constructed from a lower horizontalplate M, a curved top l5; anda pair of side Wal1s"l'6'|6. 'Aconventional vacuum pump 19 is bolted to one'side of the column ll ataposition substantially midway between its ends, the suction intake'ofthe pump l9 being connected to'the cavity'of the box [3 by a hoseconnection 20. "The pump I9 is driven by means of a V-belt pulley 2 l,'aV-belt' 22, and a"second pulley 23, the latter beingdriven by"an'electric motor 24. In order to maintain proper belt tension, themotor 24 is 'hin'gedly supported on a pin 26 carried at the'buter" endof a bracket 21,ofwhich the inner end is supported from the column I l.A cable 28 supplies electric powerto the motor 24 and an on-on electricswitch 36, 'i'scOhnectd to themo'tor by a cable 3|. The switch3llcontrols theoperation of the motor 24. The plate preregisteringmachine illustrated is a double-ended preregistering device havingregistering equipment at both the rightend and at the left end asseeninflFigs. 1 andz. ,This type ofiequipment is advantageously usedwith printing plates .having register marks on both the leading andthetrailing end thereof. Under some circumstances, however, it isdesirable to'hav register marks on only one end of theprinting plate.When thisis the case, a singleended preregistering ma'chine' will beused having registering means at only-"one end of the tableQas for;example, at the right 'end as seen in- Figs. 1- and 2.

In order to simplify the following description ofthe invention; thepreregistering"machinewill 3 be described as a single ended machine.However, it will be understood that the double ended machine asillustrated is also contemplated, the said double ended machine havinduplicate registering equipment on both the right and the left endsthereof. The duplicate registering equipment shown at the left end ofFigs. 1 and 2 is not shown in complete detail, but it will be understoodthat all of the parts shown on the right end are also provided on theleft end. The numerals used to designate the elements of the left endare the same as those used to designate the right end, except that asmall prime has been added to the numerals designating "the left endelements.

In order to support a register adjusting device, later to be described,there is provided a pair of brackets 34-34, depending from beneathopposite sides of the end portion of the plate 14. The lower ends of thebrackets 34-34 are apertured and thereby journal a transversallyextending horizontal cylindrical shaft 36 having terminals 39-39, whichextend beyond the brackets 34-34. A register device, indicated generallyby the numeral 49, is hingedly supported by means of the shaft 36.

The top [5, as best seen in Figs. 1 and 4, is curved, and preferably, iscurved as seen from the above so as to be in the form of a convexportion of a cylinder. In order that the upper surface of the top l maybe in communication with the vacuum produced within the table-box l3 bythe pump 19, the top I 5 is provided with a multiplicity of small holes41. When the machine is in operation a flexible printing plate 42, whichplate is to be registered, may be held to the upper surface of thecurved top by the suction of the holes 4 I. For convenience, the rightend, Figs. 1 and 2, of plate 42 is designated by the numeral 43.

The horizontal shaft 36 passes freely through the apertures provided inthe lower ends of the brackets 34-34 and thus the shaft may oscillatearound its center and /or slide axially of its length. The right handterminal 39', as seen in Fig. 3, of the shaft 36 has the lower end of anupstanding arm 48' secured thereto by a set screw 46. The other or leftterminal 39 of the shaft 36 carries a second upstanding arm 48, thelatter being held from axial movement along the shaft 36 by collars49-49 but at the same time being allowed to rotate slightly with respectto said shaft. The upper ends of the arms 48-48 support oppositeterminals of a horizontally extending crossbar 56, ghe arms beingfastened to the bar 59 by bolts The upper face of the cross bar 59 isprovided with an upfacing groove 52 that extends the length of the barand has a recessed portion 53. The groove 52 and recess 53 are designedto receive a plate engaging means in the form of a long plate clamp 55.This clamp is the clamp that will ultimately be used to hold one end 43of the plate 42, of a printing cylinder (not shown but disclosed in myco-pending patent application Ser. No. 165,029, filed May 29, 1950). Theclamp 55 is formed from two separate parts, viz. an upper clamp bar 56and a lower clamp bar 51. The lower bar 51, and thus the clamp 55 as awhole, is exactly positioned in the groove 52 because of a register pin68 carried by the cross bar 59. This pin 60 enters a register hole 62formed in an appropriate part of the bar 51 of the clamp 55. The upperbar 56 is held to the lower bar 51 by a plurality of spaced countersunkscrews 58. The lower side of the upper bar 56 is provided with alongitudinally extending depending tongue 59 which is devised to enteran upfacing longitudinally extending groove 61 formed in the upperportion of the lower bar 51. When the end 43 of the flexible printingplate 42 is placed between the jaw portions of the clamp bars 56-51, theplurality of screws 58 are tightened, thereby securely causing one endof the plate 42 to be held by the plate clamp 55.

The lower bar 51 and thus the plate clamp 55 as a whole is held to thecross bar 59 by being positioned in the groove 52 of the cross bar 50.The bar 51 is further accurately positioned in the groove 52 of the bar58 by having a front edge forced into tight abutment with a rear edge 63formed on the cross bar 59 and overhanging the undercut portion 53. Themeans for holding the bar 51 in the groove 52, comprises a pair ofspaced hand screws 65-65, which are screwed through threaded holesformed in a rear portion of the cross bar 58. The front ends of thesescrews engage an inclined edge 69 formed on the rear of the lower clampbar 51. It will be appreciated that tightening of the screws 65-65, notonly forces the clamp bar 51 forward against the edge 63, therebyaccurately locating the bar 51 with respect to the cross bar 50, but dueto the incline 69 and the recess 53 also retains the bar in the groove52. v 7

Each of the upstanding arms 48-48 is provided, near its upper end, withan outwardly formed extension 66 and in each case this extension 66supports an upstanding bracket 61, the upper end of which terminates ina cylindrical stud 69. Each bracket 61, and thus each stud 68, may beadjusted with respect to its respective supporting extension due to thefact that each bracket 61 is held to that extension by means of a pairof bolts 18-19, passing through slotted holes 1l-1l, formed in thebracket 61. An out reaching arm 89 is adjustabl'y clamped to each stud68, and the free or distal end of each arm 88 carries an adjustable downviewing telescopic sight 81 having the usual cross-hair lines 82, whichas will be shown hereinafter, are used to line up corresponding crossedregister marks 83-83, which are formed on the various color printingplates 42, when the said printing plates are manufactured.

A mid-portion of each bracket 34-34 carries a pivot pin 85 and this pinfreely supports the eye portion of an eye-bolt 86. A helical compressionspring 81 surrounds the stem of the bolt 36 and, due to a shoulder 88 onthe bolt 86 and an apertured lug 89, formed on each arm 48-46, the arms49-48 are biased (Figs. 1 and 4) to swing clockwise about the axis oftheir pivot shaft 36. The stem of each bolt 86 passes through anaperture in the lug 89 and the stem of the bolt is threaded as at 9|.The outer end of this threaded portion carries an adjusting hand nut 93.

A helical compression spring 96 surrounds a portion of the shaft 36 andexerts a biasing pres sure, longitudinal to the axis of the shaft. Thisbiasing force acts between a collar 91, and the bracket 34'. The forceof spring 96 is opposed by a hand screw 96 which passes through thelower part of the upstanding arm 48', the end of the screw 98 beingarranged to engage the bracket 34. Attention is here called to the factthat the adjustments effected by hand nut 93 and hand screw 98 areautomatically maintained free of backlash and self-locking, I

Operation The operation of the hereinbefore described machine will beunderstood by those skilled in the art. However, in order that there maybe no misunderstanding the following description of the use of themachine during the registration of a series of color printing plates isgiven in detail.

Before using the preregistering machine of this invention, three or fourflexible printing plates. intended for use in color printing, will beprepared by any known process, not herein described. Each of theseplates will have a pair of register marks that are exact duplicates ofthe two register marks 83-83, shown on printing plate 42. To begin with,the telescopic sights 8|l8l wi1l be adjusted so that their cross-hairs82-82 are spaced a distance to correspond exactly with the distancebetween the two register marks 83-83 on the plate 42. Then the pair ofhand nuts 93-93 are adjusted until the arms 48-48 are in a neutralposition midway between their forward and backward limits of movement.Thereafter, the hand screw 98 is adjusted until the registering device48 is in its neutral position midwaybetween its right and left handlimits. When this has been accomplished, the clamp 55 is inserted intoslot 52 of the cross bar 58 and locked in place by the hand screws 85.With the screws 58 in the bar 58 still loose, the plate 42 is placed onthe top [5 of the table It, and its right end 43 is inserted between thejaws of the upper and lower bars 58 and 51. Then the printing plate 42,which is still unclamped, is moved by hand until the register marks83-83 on the plate 42 are aligned roughly with the cross hair lines82-82 in the telescopic sights 3 l-8 I. Then the motor and vacuum pump24-l8, are started by operating the electric switch 38. This evacuatesthe box-like table [3 and creates suction through the multiplicity ofholes 4 l thereby causing the printing plate 42 to be held against theupper curved surface of the top 15. This curving of the printing platesassures that residual stresses and deformations will be relaxed and/orremoved from the plate 42.

Inspection through the magnifying sights 8l-8l will disclose smalldeviations (Fig, 5) between the cross-hair lines 82-82 of the sights8l-8l' and the register marks 83-83 carried by the printing plate 42. Bymeans of the hand screw 98, the cross bar 58 and thus the crosshairlines 82-82 of the telescopic sights 8i-8l may be moved from side toside, which is in a direction parallel to the axis of the shaft 38 andaxially of the plate cylinder (not shown) on which the plate 42 willeventually be placed. Eventually one set of parallel cross-hair lines32-82 will be colinear, in one direction, with one set of the registermarks 83-83 carried by the printing plate 42. Manipulation of the handnuts 93-93 will move the cross-bar 58 and the telescopic sights towardand away from the table in the other direction which iscircumferentially of the plate cylinder (not shown) on which the plate42 will eventually be placed. This will cause the other set ofcross-hair lines 82-82 to become colinear with the other set of registermarks 83-83. Since the plate clamp 55 is secured to the cross bar 58 bythe screws 85-85, the clamp 55 will move with the bar 50, and with thecrosshair lines 82-82 in the sights 8l-8I. Therefore a definite locationbetween the edge 63 of the plate clamp 55 and the register marks 83-83will be established. There will also be established a definite locationwith'res'pect to'the register pin 68 and the register hole 62 formed'inthe b3! 51. .1.

Now the plurality of screws 58 are tightened to cause the jaws of theclamp 55 to firmly clamp the end 43 of the flexible printing plate 42.This establishes a definite relationship axially of the plate 42,between the register marks 83-83 and the register hole 62. It alsoestablishes a definite relationship, circumferentially of the plate,between the register marks 83-83 and'the edge 83.

It will be noted that the curved shape of the plate 42, while beingregistered will remove all stresses and/or deformations residual orotherwise, from the plate 42. It will also be noted that the plate 42 isnot stressed or deformed during the registering operation. The only timethe plate 42 is moved is before the suction is applied, and at that timethe plate can be moved over the top l5 without exerting any undue forceon the plate. Once the plate is held by suction, and the actualregistration begins the cross bar 58, clamp 55, and telescopic sights 82are moved instead of moving the plate 42.

After the plate 42 has been registered, it may be removed from the topI5 by stopping the vacuum pump I8, and by releasing the end screws 65.Then the clamp 55, with the plate 42 attached thereto, may be removedfrom the preregistering machine and transferred to a printing machinehaving a plate cylinder (not shown) equipped with a groove, an edge, anda register pin that are exact duplicates of the groove 52, the edge 83and the register pin 68, it being understood that the clamp 55 entersand is secured in exactly the desired position in the groove of theplate cylinder. Such a cylinder is shown in my co-pending patentapplication Serial No. 165,029 supra.

The above has described the registering of a single printing plate thatis intended to print only one color. The companion plates that aredesigned to print other colors are registered in exactly the same way asherein shown and described, with the result that the complete series ofplates after registration will be in exact and proper register.

It will be understood that many changes may be made in the hereinbef oredescribed mechanism without departing from the spirit of the invention.Instead of employing the plate engaging clamp 55 as a reference that maybe transferred to a plate cylinder, other plate engaging references maybe employed. For example, the plate edge or end 43 may be marked, out,trimmed or drilled in such a manner as to furnish a reference that maybe transferred to a point remote from the preregistering machine andwhich may be used to register with or against registering pins orabutments. Also the plate 42 may be held to the top I5 by means otherthan a vacuum, as for example mechanical clamps may be employed.

Furthermore, register marks may be used on both the leading and trailingends of the printing plate 42. Under these circumstances a double endedtable will be used and plate engaging members will be employed at boththe right and the left end of the preregistering equipment. This isshown in Figs. 1 and 2 and comprises a complete duplication of themembers at both the right and left ends of the table. The elementsdesignated as 34, 38, 38, 48, 48, 50, 68, 88, 8|", 82, SP, 93, locatedat the left end of the table, correspond exactly to the elements 34',36, 39, 40, 48, 58, 88, 80, 8|, 82, 9|, and 93 7 previously described aslocated at the right end of the table.

In use the double ended table will be used in the same manner aspreviously described, except that the operation of registering will berepeated for both the leading and the trailing ends of the plate.

Having thus set forth the nature of my invens tion, What I claim hereinis:

1. A machine for preregistering a series of fiex-. ible printing plates,said machine comprising a support, a hollow box-like table carried bysaid support, a perforated curved top for said boxlike table, means forcreating suction in said boxlike table below said perforated top,whereby, a printing plate placed on said top will be held thereto bysuction, a pair of brackets depending from said table, a pair ofupstanding arms, pivots for supporting the lower ends of said arms fromthe lower ends of said brackets, means for sliding said armslongitudinally with respect to said pivots, a cross bar supported fromthe upper ends of said arms, telescopic sights carried by the upper endsof said arms and arranged to view portions of the printing plate, aclamp carried by said cross bar and arranged to clamp one end of saidprinting plate, a first spring for biasing said arms rotatively withrespect to said pivot, means for adjusting said first spring, a secondspring for biasing said arms longitudinally with respect to said pivot,and means for adjusting said second spring.

2. A machine for preregistering a series of flexible printing plates,said machine comprising a support, a hollow box-like table carried bysaid support, a perforated curved top for said boxlike table, means forcreating suction in said boxlike table below said perforated top wherebya printing plate placed on said top will be held thereto by suction, apair of brackets depending from said table, a pair of upstanding arms,the lower ends of said arms being pivotally supported from the lowerends of said brackets, a cross bar supported from the upper ends of saidarms, telescopic sights carried by the upper ends of said arms andarranged to view portions of the printing plate, and a clamp carried bysaid cross bar and arranged to clamp one end of said printing plate.

3. A machine for preregistering a series of flexible printing plates,said machine comprising a table for supporting said printing plates, apair of brackets depending from said table, a pair of upstanding arms, apivot for rotatively supporting said arms with respect to said brackets,means for sliding said arms longitudinally with respect to said pivot, aregister viewing device carried by said arms, a plate engaging mechanismcarried by said arms, a first spring for biasing said arms rotativelywith respect to said pivot, means for adjusting said first spring, asecond spring for biasing said arms longitudinally with respect to saidpivot, and means for adjusting said second spring.

4. A machine for preregistering a series of flexible printing plates,said machine comprising a support, a hollow box-like table carried bysaid support, a perforated curved top for said boxlike table, means forcreating suction in said boxlike table below said perforated top,whereby a printing plat placed on said top will be held thereto bysuction, a pair of brackets depending from said table, a pair ofupstanding arms, the lower ends of said arms being pivotally sup.-ported from the lower ends of said brackets, a

8 cross bar supported from the upper ends of said arms, and meanscarried by said cross bar for engaging said printing plate.

5. A machine for preregistering a series of flexible printing plates inaccordance with the preceding claim, wherein the means for engaging saidprinting plate is a clamp.

6. A machine for preregistering flexible printing plates havingregister-marks thereon, said machine comprising a support, a hollowbox-like table carried by said support, a perforated curved top for saidbox-like table, means for creating suction in said box-like table belowsaid perforated top, whereby a printing plate placed on said top will beheld thereto by suction, a movable structure mounted to have bothlateral and longitudinal movement with respect to said table, aregister-mark viewing device carried by said structure, a plate engagingmember also carried by said structure, a first adjustable connectionbetween said movable structure and said table and permitting lateraladjustment of said structure with respect to said table, and a secondadjustable connection between said movable structure and said table andpermitting longitudinal adjustment of said structure with respect tosaid table.

7. A machine for preregistering flexible printing plates, said machinecomprising a table top capable of supporting a printing plate, a pair ofbrackets depending from said table, a pair of upstanding arms, the lowerends of said arms being pivotally supported from the lower ends of saidbrackets, a cross bar supported from the upper ends of said arms, andmeans carried by said cross bar for engaging said printing plate.

8. A machine for preregistering a flexible printing plate designed to beused during a printing operation, said machine comprising a curvedsupport for said printing plate, means for holding said printing plateto said support, means for clamping one end of said plate, a membersupported by and adjustably movable with respect to said machine, aclamp for detachably conmeeting said means for clamping one end of saidplate to said last named member, and a register seeking device alsocarried as part of said last named member, whereby said printing plateis held stationary during said registering operation, said clampingmeans becoming part of said printing plate and remaining with said plateduring the printing operation.

9. A machine for preregistering a flexible printing plate, said machinecomprising a tabletop capable of supporting the printing plate, a pairof brackets depending from one end of said table, a pair of bracketsdepending from the other end of said table, upstanding arms, the lowerend of one of said upstanding arms being pivotally supported from thelower end of one of each of said depending brackets, a cross barsupported from the upper ends of two of said upstanding arms at one endof said table, a second cross bar supported from the upper ends of twoof said upstanding arms at the other end of said table, and meanscarried by both of said cross bars for engaging opposite ends of saidprinting plate.

10. A machine for preregistering flexible printing plates that carryregister marks, said machine comprising, a table-top capable ofsupporting a printing plate, means for securing said printing plate tosaid table-top, a movable cross-member mounted for both lateral andlongitudinal movement with respect to said table-top, a register viewingdevice carried by said cross-member in such a manner that saidcross-member may be accurately positioned with respect to said registermarks on said printing plate, a plate clamp carried by saidcross-member, said plate clamp being of a type suitable for holding oneend of a printing plate to a printing cylinder and said clamp engagingand clamping said plate in register relation with respect to saidregister marks, a first adjustable connection between said crossmemberand said table thereby permitting lateral adjustment of saidcross-member with respect to said table, and a second adjustableconnection between said cross-member and said table thereby permittinglongitudinal adjustment of said cross-member with respect to said table.

11. A machine for preregistering a series of flexible printing plates,said machine comprising a table for successively supporting saidprinting plates, a movable member supported by said table and saidmember being capable of both lateral and longitudinal movement relativeto said table, a register viewing device carried by said member, aplate-clamp carried by said same member, and a first screw adjustablyconnecting said movable member to said table and arranged for shiftingsaid member together with said register viewing device and saidplate-clamp laterally with respect to said printing plates, and a secondscrew adjustably connecting said movable member to said table andarranged for shifting the same member together with said registerviewing device and said plate-clamp longitudinally with respect to saidprinting plates.

12. A machine for pre-registering a flexible printing plate havingregister means thereon, said machine comprising, a curved support forsaid printing plate, means holding said printing plate fixed and inengagement with said curved support, a movable bar mounted to have bothcircumferential and axial movement with respect to said curved support,a viewing device carried by said movable bar and adapted to view theregister means on said printing plate thereby registering said movablebar with respect to said plate, a plate-clamp carried by said bar andhaving means for clamping said plate to said bar and adjustableconnections between said movable bar and said curved support.

13. A machine for pre-registering a flexible printing plate inaccordance with claim 12, wherein the movable bar which is mounted tohave both circumferential and axial movement with respect to said curvedsupport, is mounted on a pair of arms pivotally supported by saidmachine.

14. A machine for preregistering a flexible printing plate in accordancewith claim 12, wherein the movable bar is mounted on a shaft pivotallysupported by said machine, a pair of arms supported by said shaft, oneof said arms being secured to said shaft and the other of said armsbeing pivoted with respect thereto.

15. A machine for pre-registering a flexible plate adapted for useduring a printing process, comprising, means for bending said plate intoa curved form, means for holding said plate stationary in said curvedform, a plate-clamp, a member adjustably movable with respect to saidstationarily held plate, means for detachably connecting saidplate-clamp to said last named member, means for moving said member andplate-clamp with respect to said plate, means for registering saidplate-clamp with respect to said plate and means for clamping saidplate-clamp to said plate.

16. A machine for registering flexible plates adapted for use during aprinting process, comprising, means to curve said plate and therebyrelax stresses and deformations in said 'plate, vacuum means to holdsaid plate in said relaxed position, a register sight, a memberadjustably movable with respect to said machine, a plateclamp, a clampfor detachably connecting said plate-clamp to said member, meansmounting said sight on said member, and means for clamping saidplate-clamp to said plate, said plateclamp remaining attached to saidplate during the printing process.

17. A machine for pre-registering a flexible printing plate, comprising,means for holding an unregistered plate stationary with respect to saidmachine, a member located at each end of said machine, means foradjustably moving said member with respect to said machine and the plateheld stationary thereto, a pair of plateclamps of the type suitable formounting on the printing cylinder of a printing machine, a clampassociated with each of said members and detachably connecting each ofsaid plate-clamps to its respective member, and a register meansassociated with each of said members for registering each plate-clampwith respect to its respective end of said plate.

18. A machine for preregistering a series of flexible printing plates,said machine comprising a table for supporting said printing plates, apivotal member, a journal for said pivotal member carried by said table,means for sliding said pivotal member longitudinally with respect tosaid journal, a register viewing device carried by said pivotal member,a plate engaging member carried by said pivotal member, a first meansfor biasing said pivotal member rotatively with respect to said journal,means for adjusting said first means for biasing said pivotal member, asecond means for biasing said pivotal member longitudinally with respectto said journal, and means for adjusting said second means for biasingsaid pivotal member.

19. A machine for preregistering a plate adapted for use on the printingcylinder of a printing machine, comprising, means for holding anunregistered plate stationary with respect to said machine, aplate-clamp of the type suitable for mounting on the printing cylinderof a printing machine, a member adjustably movable with respect to saidmachine, means for detachably connecting said plate-clamp to saidlast-named member, means for moving said member and plate clamp withrespect to said machine and the plate held stationary thereto, means forregistering said plat clamp with respect to said plate, and means forclamping said plate-clamp to said plate in such a manner that said plateclamp becomes a part of and is removed with said plate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,067,067 Schlueter et al July 8, 1913 1,761,863 Bassist June3, 1930 1,860,361 Huebner May 31, 1932 2,104,553 Claybourn Jan. 4, 19382,339,467 Eckhard et a1 Jan. 18, 1944 2,417,496 Huebner Mar. 18, 19472,559,533 Daniels July 3, 1951

